determining 404

[Frank Leahy]

On Apr 26, 2004, at 10:13 AM, use-revolution-request at lists.runrev.com 
wrote:

> Subject: determining 404
> To: How to use Revolution <use-revolution at lists.runrev.com>
> Message-ID: <408D3C18.7030806 at fourthworld.com>
> Content-Type: text/plain; charset=us-ascii; format=flowed
>
> When obtaining a web resource, if it's 404 the server will usually
> return a page noting that for the user.  That's all well and good, but
> the 404 pages I've seen appear to be designed for human reading, and do
> not appear to have any consistent elements which would allow a machine
> to identify that the resource was not found.
>
> Is there something in the header that identifies that?
>
> How can I know when a requested URL doesn't exist?
>
> -- 
>   Richard Gaskin
>   Fourth World Media Corporation
>

You look at the first response header, it should look like

HTTP/1.1 200 OK

and if there's a 404 it will be

HTTP/1.1 404 File Not Found

You look for the status code, not the status string.

You can see this using the form at 
http://www.delorie.com/web/headers.html

-- Frank